Lisandro, Unfortunately, I'm on a windows machine and thus can't use valgrind.
I went ahead and exposed all (actually like 97%) of the contants in OpenCV to python using the method you described. Now, my wrapper works for the contants: CV_INTER_NN and CV_INTER_AREA but fails on CV_INTER_LINEAR and CV_INTER_CUBIC which have the integer values 1 and 2 respectively, when printed to the console. I haven't asked on the OpenCV lists yet because this seems to be a problem in my code or a bug in Cython (given that it all works in pure C). that will be my next stop though, if we can't figure it out here. Do you think posting the Cython generated code will help? Cheers! Chris On Wed, May 27, 2009 at 12:21 PM, Lisandro Dalcin <[email protected]> wrote: > On Wed, May 27, 2009 at 1:03 PM, Chris Colbert <[email protected]> > wrote: > > I've never used valgrind before. Any pointers? > > > > Just run > > $ valgrind python somescript.py > > You may get a lot of junk warnings because of Python's mem allocator > implementation. There is a way to suppress them, > > $ valgrind --suppressions=/path/to/valgrind-python.supp python > somescript.py > > You may have valgrind-python.supp installed somewhere (from package > python-devel), for example, in my Fedora 10 box, it is at. > > /usr/share/doc/python-devel-2.5.2/valgrind-python.supp > > Perhaps a good idea (I'm doing that) is to add an executable shell > script in your $HOME/bin (assuming that dir in on $PATH), like this: > > $ cat $HOME/bin/valgrind-py > #!/bin/sh > valgrind --suppressions=$HOME/lib/valgrind-python.supp $@ > > Then I run Python under Valgrind like this: > > $ valgrind-py python somescript.py > > You could even modify the script to add 'python' before the $@, I do > not do that just because I want to use it against many Python > versions. But perhaps this is not an issue for you. > > > > > I went back to the Cython generated C source and explicitly included the > > appropriate header file and explicitly passed CV_INTER_LINEAR (defined as > 1) > > to the C function call. Same story, it crashes. > > > > I've gone line by line now through the Cython code for that function and > I > > cant see anything wrong. You have any ideas I could try? > > > > Thanks! > > > > Chris > > > > On Wed, May 27, 2009 at 10:49 AM, Lisandro Dalcin <[email protected]> > wrote: > >> > >> On Wed, May 27, 2009 at 11:36 AM, Chris Colbert <[email protected]> > >> wrote: > >> > sometimes the docs are a bit dated. But nonetheless, those constants > are > >> > just integers defines in the header files and is where I got the > values > >> > 0-4, > >> > I used the integers in the example just to make it a bit more clear. > But > >> > 0-4 > >> > are valid constants for the call, as they worked in the pure C > example. > >> > >> Mmm... they I have no idea what's going on... Did you try to run under > >> valgrind? That usually works for me... > >> > >> > What you showed for exposing the constants however, is interesting, I > >> > have > >> > been just defining the constants as module level python integers so > they > >> > can > >> > be used from python. If defined as an enum as you show, will they > >> > be accessible from python? > >> > > >> > >> No, you have to explicitly expose them. If you declared them in some > >> pxd, let say "mycvdefs.pxd", you can write in "mycvmodule.pyx" > >> > >> CV_SOME_CONSTANT = mycvdefs.CV_SOME_CONSTANT > >> > >> > >> > >> > >> > >> > Chris > >> > > >> > On Wed, May 27, 2009 at 9:40 AM, Lisandro Dalcin <[email protected]> > >> > wrote: > >> >> > >> >> According to the docs, > >> >> > >> >> > >> >> > http://opencv.willowgarage.com/wiki/CvReference#Sampling.2CInterpolationandGeometricalTransforms > , > >> >> There are 4 possible values (you mention 5). Is that OpenCV > >> >> documentation dated? IMHO, you should use them. To expose these > >> >> constants in Cython code (likely in some pxd), you can do this: > >> >> > >> >> cdef extern from ....: > >> >> > >> >> enum: CV_INTER_NN > >> >> enum: CV_INTER_LINEAR > >> >> enum: CV_INTER_AREA > >> >> enum: CV_INTER_CUBIC > >> >> > >> >> > >> >> > >> >> On Wed, May 27, 2009 at 12:57 AM, Chris Colbert <[email protected] > > > >> >> wrote: > >> >> > So I'm wrapping the OpenCV library in Cython and its coming along > >> >> > quite > >> >> > nicely (thanks to everyone here for getting me up to speed!), but > >> >> > today > >> >> > I've > >> >> > run across a strange issue where a wrapped function fails for > certain > >> >> > values > >> >> > of integer arguments, but a pure c implementation testing the same > >> >> > thing > >> >> > with the same arguments works. > >> >> > Here is the code excerpts im using: > >> >> > #---------- .pyx ------------------# > >> >> > def cvResize(cy_cvtypes.CvArr src, cy_cvtypes.CvArr dst, > >> >> > interpolation): > >> >> > cdef c_cxcore.CvArr* c_src = src.handle() > >> >> > cdef c_cxcore.CvArr* c_dst = dst.handle() > >> >> > cdef int c_interpolation = interpolation > >> >> > with nogil: > >> >> > c_cv.cvResize(c_src, c_dst, c_interpolation) > >> >> > #-------- c_cv.pxd -----------------# > >> >> > cdef extern from "cv.h": > >> >> > void cvResize(CvArr* src, CvArr* dst, int interpolation) nogil > >> >> > > >> >> > #--------- test.py -----------------# > >> >> > from cyopencv import * > >> >> > if __name__=='__main__': > >> >> > img = cvLoadImage('2.bmp') > >> >> > img2 = cvCreateImage((640, 480), img.depth, img.nChannels) > >> >> > cvResize(img, img2, 3) > >> >> > img2.show() > >> >> > > >> >> > > >> >> > #--------- pureC.c -----------# > >> >> > #include "highgui.h" > >> >> > #include "cv.h" > >> >> > #include "cxcore.h" > >> >> > #include "cxtypes.h" > >> >> > int main(void) > >> >> > { > >> >> > IplImage* img, *img2; > >> >> > img = cvLoadImage("2.bmp", 1); > >> >> > img2 = cvCreateImage(cvSize(640, 480), img->depth, > >> >> > img->nChannels); > >> >> > cvResize(img, img2, 3); > >> >> > cvNamedWindow("test", 1); > >> >> > cvShowImage("test", img2); > >> >> > cvWaitKey(0); > >> >> > cvDestroyAllWindows(); > >> >> > cvReleaseImage(&img); > >> >> > cvReleaseImage(&img2); > >> >> > } > >> >> > > >> >> > > >> >> > valid integers for the argument 'interpolation' are 0, 1, 2, 3, 4 > (as > >> >> > tested > >> >> > with the C function). My Cython wrapper fails with a Python crash > for > >> >> > integer values 1 & 2. Values of 0,1,4 work properly and the output > >> >> > image > >> >> > matches the output image of the C test function under the same > >> >> > conditions. > >> >> > I've looked at the generated Cython code and everything seems in > >> >> > order, > >> >> > I > >> >> > just can't think of what could be causing this behavior. > >> >> > Any thoughts? > >> >> > Cheers! > >> >> > Chris > >> >> > > >> >> > _______________________________________________ > >> >> > Cython-dev mailing list > >> >> > [email protected] > >> >> > http://codespeak.net/mailman/listinfo/cython-dev > >> >> > > >> >> > > >> >> > >> >> > >> >> > >> >> -- > >> >> Lisandro Dalcín > >> >> --------------- > >> >> Centro Internacional de Métodos Computacionales en Ingeniería (CIMEC) > >> >> Instituto de Desarrollo Tecnológico para la Industria Química (INTEC) > >> >> Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) > >> >> PTLC - Güemes 3450, (3000) Santa Fe, Argentina > >> >> Tel/Fax: +54-(0)342-451.1594 > >> >> _______________________________________________ > >> >> Cython-dev mailing list > >> >> [email protected] > >> >> http://codespeak.net/mailman/listinfo/cython-dev > >> > > >> > > >> > _______________________________________________ > >> > Cython-dev mailing list > >> > [email protected] > >> > http://codespeak.net/mailman/listinfo/cython-dev > >> > > >> > > >> > >> > >> > >> -- > >> Lisandro Dalcín > >> --------------- > >> Centro Internacional de Métodos Computacionales en Ingeniería (CIMEC) > >> Instituto de Desarrollo Tecnológico para la Industria Química (INTEC) > >> Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) > >> PTLC - Güemes 3450, (3000) Santa Fe, Argentina > >> Tel/Fax: +54-(0)342-451.1594 > >> _______________________________________________ > >> Cython-dev mailing list > >> [email protected] > >> http://codespeak.net/mailman/listinfo/cython-dev > > > > > > _______________________________________________ > > Cython-dev mailing list > > [email protected] > > http://codespeak.net/mailman/listinfo/cython-dev > > > > > > > > -- > Lisandro Dalcín > --------------- > Centro Internacional de Métodos Computacionales en Ingeniería (CIMEC) > Instituto de Desarrollo Tecnológico para la Industria Química (INTEC) > Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) > PTLC - Güemes 3450, (3000) Santa Fe, Argentina > Tel/Fax: +54-(0)342-451.1594 > _______________________________________________ > Cython-dev mailing list > [email protected] > http://codespeak.net/mailman/listinfo/cython-dev >
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